1. Field of the Invention
This invention pertains generally to a device and method for determining the position, velocity, and other parameters for a satellite and more specifically to an apparatus and method for determining the positions, velocities and other parameters of a multiple of satellites, or celestial bodies.
2. Description of the Related Prior Art
Highly automated, accurate, and reliable orbit determination processing is required for large scale satellite networks. Reliable automatic processing reduces the cost of operating a satellite network by reducing the need for expert orbit determination.
Several general purpose orbit determination and prediction techniques exist today, however, none of these techniques automatically processes raw tracking data and process as finished orbit products and analyses using Batch Least Squares; simultaneously compute orbits and covariance for complex networks of multiple satellites, using multiple ground stations with various tracking measurement types; computes relative satellite trajectories in which one satellite orbit is determined very accurately with respect to another satellite orbit; identifies calibration anomalies in tracking network components by combining tracking measurements; and incorporates state-of-the-art dynamical models that allow rapid update to newer models when they become available. Because of this the following difficulties arise; in the absence of robust automatic operations, skilled orbit analysts must intervene to cull bad observations by manually examining observation errors; most existing orbit determination techniques are designed to process one satellite at a time, requiring large-scale satellite networks to be processed serially. Relative navigation requirements are typically addressed by custom program techniques on a case-by-case basis. Also, calibration anomalies have typically been identified by a parametric series of orbit determination computations where sets of parameters are held constant or estimated in a brute force attempt to isolate error sources; and the roots of most orbit determination techniques available today can be traced back to the beginning of the space age. The codes within these techniques are often undocumented, hard to read, and harder to update. Large expenditures are often incurred when model updates are required.